Service control method and apparatus

ABSTRACT

In the field of mobile communications, embodiments of the present invention disclose a service control method and apparatus. A user equipment has established a circuit switched bearer, and the user equipment initiates a session with a third party. The method includes: receiving, by a service centralization and continuity application server SCC AS, early session media information and sending the early session media information to a circuit switched network in a form of regular session media, so that the circuit switched bearer is used for an early session; and receiving, by the SCC AS, an off-hook signal of the third party and sending regular session media information of the third party to the circuit switched network, so that the circuit switched bearer is used for a regular session.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2011/071181, filed on Feb. 23, 2011, which claims priority toChinese Patent Application No. 201010126135.4, filed on Mar. 2, 2010,both of which are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to the field of mobile communications, andin particular, to a service control method and apparatus.

BACKGROUND OF THE INVENTION

With the rapid development of an IMS (IP Multimedia Subsystem) in thefield of telecommunication, an IMS network is becoming widely applied.However, the IMS network will not be fully deployed in a short period oftime. Moreover, it is impossible to provide all CS (Circuit Switch)network users with new IMS terminals instead in a short period of time.Therefore, conventionally a CS network still has to coexist with the IMSnetwork. As a result, simultaneous operation of CS and IMS serviceplatforms increases the cost of constructing new services and theoperating cost.

To meet a requirement of coexistence of the CS network and the IMSnetwork at present, a CS network service logic function may betransferred to the IMS network to implement a united service platform,so as to reduce the cost of constructing and operating new services.Such technology is referred to as an ICS (IMS Centralized Service). TheICS may also be regarded as a new IMS session, in which the IMS sessionis supported to use a CS bearer (Bearer), which is alternativelyreferred to as a CS media, to transmit media streams, and multiple IMSsessions may share one CS bearer. The CS bearer is established through aCS call, where the CS call is converted into an IMS call by an MSCserver (Mobile Switch Center server) or an MGCF (Media Gateway ControlFunction). An SCC AS (Service Centralization and Continuity ApplicationServer) that supports the ICS is an IMS application based on a homenetwork. A UE (User equipment) that supports the ICS establishes aservice control channel with the SCC AS to transmit IMS service controlsignaling (such as call initiation, transfer and release), where theservice control channel is based on a Gm interface or an I1 interface.

The terms “call” and “session” are not distinguished in this document,and are able to be replaced with each other.

CAT (Customized Alerting Tones), generally known as color ring backtones, are a service triggered in a phase of a session setup, and arecapable of presenting multimedia information (such as one of or acombination of a speech, a video and a text) to a calling party toreplace a conventionally used monotonous ringback tone (for prompting aring to a called terminal). The CAT may also be regarded as a newringback tone, which allows a user or an operator to customize mediacontent of the ringback tone.

The CAT, which mainly transmits media streams before the called terminalsends an off-hook signal, belongs to an early session (or referred to asearly media), and a regular session (that is, transmission of a normalcall media streams) is performed after the off-hook signal. Anothercommon type of early media is Announcement, for example, for promptingthe user that “the network is busy, please dial again later”. The earlymedia mainly have three service models: a gateway model, a forking modeland an early-session model. The early media may still exist after theoff-hook signal. For example, the CAT media may serve as, for example,background music or a background video, after a normal session starts.

As regards implementing the early media (for example, a CAT service)during ICS session setup, the inventor finds the following problems:

While initiating setup of a first ICS session, an ICS UE also initiatessetup of a CS call, where the CS call is converted into an IMS call bythe MSC server or the MGCF. Therefore, the MSC server or the MGCFsupports the early media at this time. However, when the ICS UEinitiates a second ICS session, an existing CS bearer is reused, thatis, a setup process of a CS call does not exist, and therefore, the MSCserver or the MGCF does not support the early media.

As for a case of forking of the called party occurring in the setup ofthe ICS session, the following problems exist:

Similar to the early media, the forking is also a mechanism of the callsetup process. Therefore, when the ICS UE initiates the second ICSsession, the MSC server or the MGCF cannot support the forking.

SUMMARY OF THE INVENTION

In order to solve a problem that, an MSC server or an MGCF does notsupport early media because an existing CS bearer is reused and therebya CS call setup process does not exist when an ICS UE initiates a secondICS session, the embodiments of the present invention provide a servicecontrol method and apparatus, and the solutions are as follows:

An embodiment of the present invention provides a service controlmethod, where a user equipment has established a circuit switchedbearer, and the user equipment initiates a session with a third party.The method includes:

receiving, by a service centralization and continuity application serverSCC AS, early session media information, and sending the early sessionmedia information to a circuit switched network in a form of regularsession media, so that the circuit switched bearer is used for an earlysession;

receiving, by the SCC AS, an off-hook signal of the third party, andsending regular session media information of the third party to thecircuit switched network, so that the circuit switched bearer is usedfor a regular session; or

receiving, by the SCC AS, the regular session media information of thethird party, where the regular session media information of the thirdparty and the early session media information come from one same dialog,and sending the regular session media information of the third party tothe circuit switched network, so that the circuit switched bearer isused for the regular session.

An embodiment of the present invention provides a service controlmethod, where a user equipment has established a circuit switchedbearer, and the user equipment initiates a session with a third party.The method includes:

receiving, by a service centralization and continuity application serverSCC AS, regular session media information of a first user equipment ofthe third party, and sending the regular session media information ofthe first user equipment of the third party to a circuit switchednetwork, so that the circuit switched bearer is used for connecting thefirst user equipment of the third party; and

receiving, by the SCC AS, an off-hook signal of a second user equipmentof the third party, and sending regular session media information of thesecond user equipment of the third party to the circuit switchednetwork, so that the circuit switched bearer is used for connecting thesecond user equipment of the third party.

An embodiment of the present invention provides a service controlmethod, where a user equipment has established a circuit switchedbearer, and the user equipment initiates a session with a third party.The method includes:

receiving, by the user equipment, early session media information, andusing the circuit switched bearer to perform an early session; and

receiving, by the user equipment, an off-hook signal of the third party,and using the circuit switched bearer to perform a regular session.

An embodiment of the present invention provides a service controlmethod, where a user equipment has established a circuit switchedbearer, and the user equipment initiates a session with a third party.The method includes:

receiving, by the user equipment, media information of a first userequipment of the third party, and using the circuit switched bearer toconnect the first user equipment of the third party; and

receiving, by the user equipment, an off-hook signal of a second userequipment of the third party, and using the circuit switched bearer toperform a regular session with the second user equipment of the thirdparty.

An embodiment of the present invention provides a service centralizationand continuity application server SCC AS, where a user equipment hasestablished a circuit switched bearer, and the user equipment initiatesa session with a third party. The SCC AS includes:

an early session media information processing module, configured toreceive early session media information, and send the early sessionmedia information to a circuit switched network in a form of regularsession media, so that the circuit switched bearer is used for an earlysession; and

a regular session media information processing module, configured toreceive an off-hook signal of the third party, and send regular sessionmedia information of the third party to the circuit switched network, sothat the circuit switched bearer is used for a regular session; orconfigured to receive the regular session media information of the thirdparty, where the regular session media information of the third partyand the early session media information come from one same dialog, andsend the regular session media information of the third party to thecircuit switched network, so that the circuit switched bearer is usedfor the regular session.

An embodiment of the present invention further provides a servicecentralization and continuity application server SCC AS, where a userequipment has established a circuit switched bearer, and the userequipment initiates a session with a third party. The SCC AS includes:

a first user equipment processing module, configured to receive regularsession media information of a first user equipment of the third party,and send the regular session media information of the first userequipment of the third party to a circuit switched network, so that thecircuit switched bearer is used for connecting the first user equipmentof the third party; and

a second user equipment processing module, configured to receive anoff-hook signal of a second user equipment of the third party, and sendregular session media information of the second user equipment of thethird party to the circuit switched network, so that the circuitswitched bearer is used for connecting the second user equipment of thethird party.

In the solutions according to the embodiments of the present invention,the SCC AS sends the early session media information to the CS networkin the form of regular session media, or the SCC AS saves second regularsession media information caused by forking execution instead ofimmediately sending the information to the CS network, thereby screeningthe early session or forking execution for the MSC Server or the MGCF ofthe CS network during a setup process of the second ICS session, andsolving problems that the MSC server or the MGCF does not support theearly media and that when the ICS UE initiates the second ICS session,forking of multiple user equipments of a called party (the third party)cannot be supported. Therefore, the use experience is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of processing of a service control methodaccording to Embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of processing of another service controlmethod according to Embodiment 1 of the present invention;

FIG. 3 is a schematic flow chart of a service control method when an SCCAS receives a forking response carrying CAT media information firstaccording to Embodiment 2 of the present invention;

FIG. 4 is a schematic flow chart of a service control method when an SCCAS receives a forking response carrying regular session mediainformation first according to Embodiment 2 of the present invention;

FIG. 5 is a schematic flow chart of a service control method when a 1xxtemporary response received by an SCC AS carries an early-session SDPoffer but does not carry a regular session SDP answer according toEmbodiment 3 of the present invention;

FIG. 6 is a schematic flow chart of a service control method when a 1xxtemporary response received by an SCC AS carries both an early-sessionSDP offer and a regular session SDP answer according to Embodiment 3 ofthe present invention;

FIG. 7 is a schematic flow chart of a service control method of aforking response that is not caused by CAT according to Embodiment 4 ofthe present invention;

FIG. 8 is a schematic flow chart of a service control method when agateway model is used according to Embodiment 5 of the presentinvention;

FIG. 9 is a schematic structural diagram of an SCC AS according toEmbodiment 6 of the present invention;

FIG. 10 is a schematic structural diagram of another SCC AS according toEmbodiment 6 of the present invention;

FIG. 11 is a schematic structural diagram of a service control systemaccording to Embodiment 7 of the present invention; and

FIG. 12 is a schematic structural diagram of another service controlsystem according to Embodiment 7 of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To make the objectives, the technical solutions, and advantages of thepresent invention more clearly, embodiments of the present invention aredescribed in more detail in the following with reference to theaccompanying drawings.

Embodiment 1

This embodiment of the present invention provides a service controlmethod, where a user equipment has established a circuit switchedbearer, and the user equipment initiates a session with a third party.Referring to FIG. 1, the method includes the following steps:

101: A service centralization and continuity application server SCC ASreceives early session media information and sends the early sessionmedia information to a circuit switched network in a form of regularsession media, so that the circuit switched bearer is used for an earlysession.

102: The SCC AS receives an off-hook signal of the third party, andsends regular session media information of the third party to thecircuit switched network, so that the circuit switched bearer is usedfor a regular session; or

the SCC AS receives the regular session media information of the thirdparty, where the regular session media information of the third partyand the early session media information come from one same dialog, andsends the regular session media information of the third party to thecircuit switched network, so that the circuit switched bearer is usedfor the regular session.

A manner for obtaining the regular session media information of thethird party includes:

receiving and saving, by the SCC AS, the regular session mediainformation of the third party when or before the SCC AS receives theoff-hook signal of the third party; or

obtaining, by the SCC AS, the regular session media information from thethird party after the SCC AS receives the off-hook signal of the thirdparty; or

receiving and saving, by the SCC AS, the regular session mediainformation of the third party when or before the SCC AS receives theearly session media information.

A gateway model or a forking model or an early-session model is used forthe early session.

This embodiment of the present invention further provides a servicecontrol method, where a user equipment has established a circuitswitched bearer, and the user equipment initiates a session with a thirdparty. Referring to FIG. 2, the method includes the following steps:

201: A service centralization and continuity application server SCC ASreceives regular session media information of a first user equipment ofthe third party, and sends the regular session media information of thefirst user equipment of the third party to a circuit switched network,so that the circuit switched bearer is used for connecting the firstuser equipment of the third party.

202: The SCC AS receives an off-hook signal of a second user equipmentof the third party, and sends regular session media information of thesecond user equipment of the third party to the circuit switchednetwork, so that the circuit switched bearer is used for connecting thesecond user equipment of the third party.

A manner for obtaining the regular session media information of thesecond user equipment of the third party include:

receiving and saving, by the SCC AS, the regular session mediainformation of the second user equipment of the third party when orbefore the SCC AS receives the off-hook signal of the second userequipment of the third party; or

obtaining, by the SCC AS, the regular session media information from thesecond user equipment of the third party after the SCC AS receives theoff-hook signal of the second user equipment of the third party.

This embodiment of the present invention further provides a servicecontrol method, where a user equipment has established a circuitswitched bearer, and the user equipment initiates a session with a thirdparty. The method includes:

receiving, by the user equipment, early session media information, andusing the circuit switched bearer to perform an early session; and

receiving, by the user equipment, an off-hook signal of the third party,and using the circuit switched bearer to perform a regular session.

This embodiment of the present invention further provides a servicecontrol method, where a user equipment has established a circuitswitched bearer, and the user equipment initiates a session with a thirdparty. The method includes:

receiving, by the user equipment, media information of a first userequipment of the third party, and using the circuit switched bearer toconnect the first user equipment of the third party; and

receiving, by the user equipment, an off-hook signal of a second userequipment of the third party, and using the circuit switched bearer toperform a regular session with the second user equipment of the thirdparty.

In the methods provided in this embodiment of the present invention, theSCC AS sends the early session media information to the CS network inthe form of regular session media, or the SCC AS saves second regularsession media information caused by forking execution instead ofimmediately sending the information to the CS network, thereby screeningthe early session or forking execution for the MSC Server or the MGCF ofthe CS network during a setup process of a second ICS session, andsolving problems that the MSC server or the MGCF does not support theearly media and that when an ICS UE initiates the second ICS session,forking of multiple user equipments of a called party (the third party)cannot be supported. Therefore, use experience of a user is improved.

Embodiment 2

For a scenario where a forking model is used for a CAT service duringsetup of a second ICS session, this embodiment of the present inventionprovides a service control method, the specific content is as follows:

(1) An SCC AS receives a forking response carrying CAT media informationfirst.

When receiving the forking response carrying the CAT media information,the SCC AS sends the CAT media information carried in the response to anMSC Server or an MGCF, so as to connect a CS bearer and a CAT mediaserver. The CAT media server may be integrated with a CAT applicationserver (CAT AS), or may also be an independent media processing serverfor playing CAT media streams. After receiving an off-hook signal, theSCC AS sends regular session media information of a called party (athird party) to the MSC Server or the MGCF (the MSC Server or the MSC isan edge device of a CS network and used for interconnection between theCS network and an IMS network) by using an UPDATE or re-INVITE method,so as to connect the CS bearer and the called party (the third party).

First, UE 1 (an ICS UE) and UE 2 have already set up an ICS session (UE1 transmits service control signaling with the SCC AS by using a Gminterface, where the GM interface is implemented through a PS network),and implement a call. Session media streams are transmitted through theCS bearer. Then, UE 1 holds (hold) the session and initiates a sessionwith UE 3 (the third party). Referring to FIG. 3, the specificprocessing process is as follows:

301: UE 1 sends a SIP INVITE 1 message to the SCC AS through the Gminterface, to initiate a session with UE 3.

The INVITE message includes an SDP offer 1, where the SDP offer 1indicates that the session uses the CS bearer. SDP stands for thesession description protocol, and an SDP offer/answer mechanism is usedto perform session negotiation. SIP stands for the session initiationprotocol, and all messages in this process are SIP messages.

302: The SCC AS receives the SIP INVITE 1 message, and sends a re-INVITEthat does not carry the SDP offer 1 to the MSC Server or the MGCF.

303: The MSC Server or the MGCF returns 200 OK that includes an SDPoffer 2, where the SDP offer 2 carries media information of the CSbearer.

If the SCC AS has already saved the media information of the CS bearer,steps 302 and 303 may be skipped.

304: The SCC AS generates a new SDP offer 3 based on the SDP offer 1 andthe SDP offer 2, and sends the SDP offer 3 to a CAT AS through a newINVITE 2.

The CAT AS is a home AS of UE 3.

305 a-305 c: The CAT AS reserves CAT resources; the CAT AS forwards theSDP offer 3 to UE 3 through a new INVITE 3; and UE 3 returns a 180response to the CAT AS.

306: The CAT AS sends a reliable temporary response, namely, a 183response, to the SCC AS.

The 183 response includes an SDP answer 3 for the SDP Offer 3, where theSDP answer 3 includes CAT media information. A P-Early-Media headerfield may be used to indicate existence of CAT early media information(for example, P-Early-Media: sendrecv, and P-Early-Media: sendonly).Definitely, any other manner may also be used for indication, which isnot limited in this embodiment of the present invention.

307: The SCC AS sends an ACK to the MGCF or the MSC Server.

The ACK sent by the SCC AS includes an SDP answer 2 for the SDP Offer 2,where the SDP answer 2 includes the CAT media information (or mayinclude a part of the CAT media information, and the rest part of theCAT media information may be transmitted through the PS network), sothat the CS bearer is connected to the CAT media server.

The ACK carries the CAT media information in the form of regular sessionmedia information, that is, the ACK does not include early mediaindication information. The MSC Server or the MGCF regards that themedia information is used for a regular session.

If steps 302, 303 and 307 are not performed, the SCC AS sends the CATmedia information to the MGCF or the MSC Server through an UPDATE or are-INVITE.

308: The SCC AS sends a reliable temporary response, for example, a 183response, which includes an SDP answer 1 for the SDP Offer 1, to UE 1through the Gm interface, where the SDP answer includes the CAT mediainformation, which mainly enables UE 1 to know existence of the CATservice and/or to perform a CAT control operation. It is also possiblethat a part of the CAT media streams is transmitted through the PSnetwork.

309: UE 1 returns a PRACK to the SCC AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

310: The SCC AS sends a PRACK to the CAT AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

311: The CAT AS activates the CAT media streams.

312: The CAT AS returns 200 OK to the SCC AS, which serves as anacknowledgment for the PRACK.

313: The SCC AS sends 200 OK to UE 1, which serves as an acknowledgmentfor the PRACK.

According to the preceding process 301-313, UE1 is connected to the CATmedia server through the CS bearer, so that the CAT service is performedwhen UE 1 and UE 3 set up a second ICS session (that is, UE 1 receivesthe CAT media streams through the CS bearer). The following stepsdescribe that UE 1 is connected to UE 3 through the CS bearer toimplement a practical call, and are specifically as follows:

314: The CAT AS receives a 200 OK off-hook signal that is sent by UE 3and includes an SDP answer 4 for the SDP Offer 3, where the SDP answer 4includes regular session media information (that is, media informationof UE 3), and the CAT AS sends the 200 OK off-hook signal to the SCC ASto forward the regular session media information.

The off-hook signal 200 OK is meanwhile a forking response, that is, a200 OK response and the 183 response in step 306 are sent by the SCC ASthrough two dialogs (dialogs), respectively.

315: The CAT AS stops the CAT media streams.

316: The SCC AS sends an UPDATE or a re-INVITE that includes a new SDPoffer 4 to the MGCF or the MSC Server, where the SDP offer 4 includesthe regular session media information of UE 3.

317: The MGCF or the MSC Server returns 200 OK that includes an SDPanswer 5 to the SCC AS, where the SDP answer 5 includes the mediainformation of the CS bearer.

At this time, the SCC AS does not necessarily send the media informationof the CS bearer to UE 3, because UE 3 has obtained the mediainformation of the CS bearer through the SDP Offer 3 sent by the CAT ASin step 305.

318: The SCC AS sends a 200 OK off-hook signal that includes an SDPanswer 6 for the SDP offer 1 to UE 1, to indicate that the session setupis successful, where the SDP answer 6 carries the regular session mediainformation.

319: UE 1 sends an ACK to the SCC AS, which serves as an acknowledgmentfor the 200 OK.

320 a-320 b: The SCC AS sends an ACK to the CAT AS, and the CAT AS sendsan ACK to UE 3.

Till now, a media connection is established between UE 3 and the CSbearer. UE 1 transmits the session media streams with UE 3 through theCS bearer to perform the regular session (that is, the practical call).The preceding process is also applicable to a case of I1 interface,where UE 1 transmits service control signaling with the SCC AS by usingthe I1 interface (the I1 interface is implemented through the CSnetwork), and a protocol used is an I1 application protocol.

(2) After an SCC AS receives a forking response carrying regular sessionmedia information first before receiving a forking response carrying CATmedia information, and the following two processing methods exist:

Processing method 1: Send the regular session media information to anMSC Server or an MGCF through an ACK, so that a CS bearer is connectedto UE 3.

When the SCC AS decides that this session setup does not activate a CATservice (for example, a calling UE 1 user forbids the CAT service, or ahome IMS network of UE 1 forbids the CAT service), that is, the SCC ASdecides that no CAT media information will be received subsequently,this method may be adopted.

If the SCC AS subsequently receives the forking response carrying theCAT media information, the SCC AS needs to connect the CS bearer to aCAT media server again.

Processing method 2: The SCC AS waits a certain period of time (thewaiting time may be set flexibly). If a forking response carrying theCAT media information is received within a certain period of time (forexample, 0.2 s), the CAT media information is sent to the MSC Server orthe MGCF through an ACK, so that the CS bearer is connected to the CATmedia server. If a forking response carrying the CAT media informationis not received during a certain period of time (for example, 0.2 s), itis assumed that no CAT service is activated, and an operation ofconnecting the CS bearer to called UE 3 is performed.

Referring to FIG. 4, the second processing method is taken as an examplebelow to describe the specific processing process:

First, UE 1 (an ICS UE) and UE 2 have already set up an ICS session (UE1 transmits service control signaling with the SCC AS by using an I1interface, where the adopted protocol is an I1 application protocol),and implement a call. Session media streams are transmitted through theCS bearer. Then, UE 1 holds (hold) the session and initiates a sessionwith UE 3.

401: UE 1 sends an I1 INVITE message to the SCC AS through the I1interface, to initiate the session with UE 3, where the I1 INVITEmessage is a session initiation message defined on the I1 interface andis an I1 application protocol message rather than a SIP protocolmessage. Different from the SIP protocol, the I1 application protocol isa lightweight protocol, and a message of the I1 application protocolcannot include an SDP offer/answer. In this process, all the I1 protocolmessages carry an I1 prefix, and other messages are SIP messages.

402: The SCC AS sends a re-INVITE that does not carry an SDP offer 1 tothe MSC Server or the MGCF.

If the SCC AS has already saved the media information of the CS bearer,steps 402 and 403 may be skipped.

403: The MSC Server or the MGCF returns 200 OK that includes an SDPoffer 2, where the SDP offer 2 carries the media information of the CSbearer.

404: The SCC AS generates a new SDP offer 3 based on the received I1INVITE and SDP offer 2, and sends the SDP offer 3 to a CAT AS through anINVITE 2.

The CAT AS is a home AS of UE 3.

405: The CAT AS reserves CAT resources; the CAT AS forwards the SDPoffer 3 to UE 3; and UE 3 returns a 180 response to the CAT AS.

406: The CAT AS sends a reliable temporary response, namely, a 183response, to the SCC AS.

The 183 response includes an SDP answer 3 for the SDP Offer 3, where theSDP answer 3 includes regular session media information, that is, mediainformation of UE 3. The SCC AS may save the regular session mediainformation or save only media information of the part of regularsession media that is transmitted by using the CS bearer, and then waitsa certain period of time for the CAT media information, where thewaiting time may be set flexibly according to an actual situation, whichis not limited in this embodiment of the present invention.

407: The SCC AS sends a PRACK to the CAT AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

408: The CAT AS returns 200 OK to the SCC AS, which serves as anacknowledgment for the PRACK.

409: In a certain waiting time, the CAT AS sends a reliable temporaryresponse, namely, a 183 response, to the SCC AS, where the 183 responseincludes an SDP answer 4 for the SDP Offer 3, and the SDP answer 4includes the CAT media information. This 183 response and the 183response in step 406 are sent through two dialogs (dialogs),respectively, that is, the CAT AS performs a forking function.

410: The SCC AS sends an ACK that includes an SDP answer 2 for the SDPOffer 2 to the MGCF or the MSC Server, where the SDP answer 2 includesthe CAT media information, so that the CS bearer is connected to the CATmedia server.

The ACK carries the CAT media information in a form of regular sessionmedia information, that is, the ACK does not include early mediaindication information. The MSC Server or the MGCF regards that themedia information is used for a regular session.

If steps 402, 403 and 410 are not performed, the SCC AS sends the CATmedia information to the MGCF or the MSC Server through an UPDATE or are-INVITE.

411: The SCC AS sends an I1 Progress message that includes a ringingindication to UE 1.

412: The SCC AS sends a PRACK to the CAT AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

413: The CAT AS activates CAT media streams.

414: The CAT AS returns 200 OK, which serves as an acknowledgment forthe PRACK.

At this time, UE1 is connected to the CAT media server through the CSbearer, so that the CAT service is performed when UE 1 and UE 3 set up asecond ICS session (that is, UE 1 receives the CAT media streams throughthe CS bearer). The following steps describe that UE 1 is connected toUE 3 through the CS bearer to implement a practical call, which arespecifically as follows:

415: The CAT AS receives a 200 OK off-hook signal sent by UE 3, andsends the 200 OK off-hook signal to the SCC AS.

416: The CAT AS stops the CAT media streams.

417: The SCC AS sends an UPDATE (or a re-INVITE) that includes a new SDPoffer 4 to the MGCF or the MSC Server, where the SDP offer 4 carries thesaved regular session media information.

418: The MGCF or the MSC Server returns 200 OK to the SCC AS.

419: The SCC AS sends an I1 SUCCESS message to UE 1, to indicate thatthe session setup is successful.

420: The SCC AS sends an ACK to the CAT AS, and the CAT AS sends an ACKto UE 3.

Till now, a media connection is established between UE 3 and the CSbearer. And UE 1 transmits the session media streams with UE 3 throughthe CS bearer, to perform the regular session (that is, the practicalcall).

The preceding process is also applicable to a case of a Gm interface.

In the method according to this embodiment of the present invention,when the forking model is used for the CAT service, the SCC AS receivesCAT early session media information through the forking response, andsends the CAT early session media information to the MSC Server or theMGCF of the circuit switched network in the form of regular sessionmedia information, so that the circuit switched bearer is used for a CATearly session. The SCC AS receives the off-hook signal of the thirdparty (the off-hook signal and the CAT early session media informationcome from different dialogs caused by the forking), and sends theregular session media information of the third party to the MSC Serveror the MGCF of the circuit switched network, so that the circuitswitched bearer is used for the regular session, thereby solving aproblem that, when the forking model is used for the CAT service and asecond ICS session is set up, the CAT service cannot be used normally.Therefore, use experience of a user is improved.

Embodiment 3

For a scenario where an early-session model is used for a CAT serviceduring setup of a second ICS session, this embodiment of the presentinvention provides a service control method. A Gm interface is taken asan example for description below, the specific content is as follows:

(1) A reliable temporary response that is received by an SCC AS andcarries an early-session SDP offer but does not carry a regular sessionSDP answer is taken as an application scenario for description. In thefollowing processing process, UE 1 and UE 2 have already set up an ICSsession (UE 1 transmits session control signaling with the SCC AS byusing a Gm interface), and implement a call. Session media streams aretransmitted through a CS bearer. Then, UE 1 holds (hold) the sessionwith UE 2 and initiates a session with UE 3. Referring to FIG. 5, thespecific processing process is as follows:

501: UE 1 sends an INVITE 1 message to the SCC AS, to initiate a sessionwith UE 3.

The INVITE message includes an SDP offer 1, where the SDP offer 1indicates the session uses the CS bearer. SDP stands for the sessiondescription protocol, and an SDP offer/answer mechanism is used toperform session negotiation.

502: The SCC AS receives the INVITE 1 message, and sends a re-INVITEthat does not carry the SDP offer 1 to an MSC Server or an MGCF.

503: The MSC Server or the MGCF returns 200 OK that includes an SDPoffer 2, where the SDP offer 2 carries session media information of theCS bearer.

If the SCC AS has already saved the media information of the CS bearer,steps 502 and 503 may be skipped.

504: The SCC AS generates a new SDP offer 3 based on the SDP offer 1 andthe SDP offer 2, and sends the SDP offer 3 to a CAT AS through a newINVITE 2.

The CAT AS is a home AS of UE 3.

505: The CAT AS reserves CAT resources; the CAT AS forwards the SDPoffer 3 to UE 3 through a new INVITE 3; and UE 3 returns a 180 responseto the CAT AS for acknowledgement.

506: The CAT AS sends a reliable temporary response, for example, a 183response, to the SCC AS.

The 183 response includes an early-session SDP offer 4 to carry CATmedia information. For example, a Content-Disposition header field maybe set to early-session, indicating that the 183 response carries theearly-session SDP offer. Definitely, any other manner may also be usedfor indication, which is not limited in this embodiment of the presentinvention.

507: The SCC AS sends an ACK to the MGCF or the MSC Server.

The ACK sent by the SCC AS includes an SDP answer 2 for the SDP Offer 2,where the SDP answer 2 includes the CAT media information (or mayinclude a part of the CAT media information, and the rest part of theCAT media may be transmitted through a PS domain), so that the CS beareris connected to a CAT media server.

The ACK carries the CAT media information in a form of regular sessionmedia information, that is, the ACK does not include early mediaindication information. The MSC Server or the MGCF regards that themedia information is used for a regular session.

508: The SCC AS sends a reliable temporary response, for example, a 183response, to UE 1, where the reliable temporary response includes theCAT media information.

509: UE 1 returns a PRACK to the SCC AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

510: The SCC AS sends a PRACK that includes an early-session SDP answer4 for the early-session SDP offer 4 to the CAT AS, which serves as anacknowledgement for the received reliable temporary response, namely,the 183 response.

511: The CAT AS activates CAT media streams.

512: The CAT AS returns 200 OK to the SCC AS, which serves as anacknowledgment for the PRACK.

513: The SCC AS sends 200 OK to UE 1, which serves as an acknowledgmentfor the PRACK.

According to the preceding process 501-513, UE1 is connected to the CATmedia server through the CS bearer, so that the CAT service is performedwhen UE 1 and the called UE 3 set up a second ICS session (that is, UE 1receives the CAT media streams through the CS bearer). The followingsteps describe that UE 1 is connected to the called UE 3 through the CSbearer to implement a practical call, and are specifically as follows:

514: The CAT AS receives a 200 OK off-hook signal (including mediainformation of UE 3) sent by UE 3, sends the 200 OK off-hook signal thatincludes an SDP answer 3 for the SDP Offer 3 to the SCC AS, where theSDP answer 3 includes the media information of UE 3, that is, regularsession media information.

The 200 OK sent by the CAT AS and the 183 response in step 506 use thesame Dialog (dialog).

515: The CAT AS stops the CAT media streams.

516: The SCC AS sends an UPDATE or a re-INVITE that includes a new SDPoffer 5 to the MGCF or the MSC Server, where the SDP offer 5 includesthe regular session media information.

517: The MGCF or the MSC Server returns 200 OK to the SCC AS.

Till now, a media connection is established between UE 3 and the CSbearer.

518: The SCC AS sends a 200 OK off-hook signal that includes an SDPanswer 1 for the SDP offer 1 to UE 1, to indicate that the session setupis successful, where the SDP answer 1 carries the regular session mediainformation.

519: UE 1 sends an ACK to the SCC AS, which serves as an acknowledgmentfor 200 OK.

520: The SCC AS sends an ACK to the CAT AS, and the CAT AS sends an ACKto UE 3.

At this time, a media connection is established between UE 3 and the CSbearer. UE 1 transmits session media streams with UE 3 through the CSbearer, to perform a regular session.

(2) A reliable temporary response that is received by an SCC AS andcarries both an early-session SDP offer and a regular session SDP answeris taken as an application scenario for description.

In the following processing process, UE 1 and UE 2 have already set upan ICS session (UE 1 transmits session control signaling with the SCC ASby using a Gm interface), and implement a call. Session media streamsare transmitted through a CS bearer. Then, UE 1 holds (hold) UE 2 andinitiates a session with UE 3. Referring to FIG. 6, the specificprocessing process is as follows:

601: UE 1 sends an INVITE 1 message to the SCC AS, to initiate a sessionwith UE 3.

The INVITE message includes an SDP offer 1, where the SDP offer 1indicates that the session uses the CS bearer. SDP stands for thesession description protocol, and an SDP offer/answer mechanism is usedto perform session negotiation.

602: The SCC AS receives the INVITE 1 message, and sends a re-INVITEthat does not carry the SDP offer 1 to an MSC Server or an MGCF.

603: The MSC Server or the MGCF returns 200 OK that includes an SDPoffer 2, where the SDP offer 2 carries session media information of theCS bearer.

If the SCC AS has already saved the media information of the CS bearer,steps 602 and 603 may be skipped.

604: The SCC AS generates a new SDP offer 3 based on the SDP offer 1 andthe SDP offer 2, and sends the SDP offer 3 to a CAT AS through a newINVITE 2.

The CAT AS is a home AS of UE 3.

605: The CAT AS reserves CAT resources.

606: The SCC AS receives a reliable temporary response, for example, a183 response, sent by the CAT AS, where the 183 response includes anearly-session SDP offer 4 to carry CAT media information and an SDPanswer 3 to carry regular session media information (that is, mediainformation of UE 3), and the SCC AS saves the regular session mediainformation.

607: The SCC AS sends an ACK to the MGCF or the MSC Server.

The ACK sent by the SCC AS includes an SDP answer 2 for the SDP Offer 2,where the SDP answer 2 includes the CAT media information (or mayinclude a part of the CAT media information, and the rest part of theCAT media information may be borne through a PS domain), so that the CSbearer is connected to a CAT media server.

The ACK carries the CAT media information in a form of regular sessionmedia information, that is, the ACK does not include early mediaindication information, so that the MSC Server or the MGCF regards thatthe media information is used for a regular session.

608: The SCC AS sends a reliable temporary response, for example, a 183response, which includes the SDP answer 3 and the early-session SDPoffer 4 to UE 1, where the early-session SDP offer 4 includes the CATmedia information.

609: UE 1 sends a PRACK to the SCC AS, which serves as anacknowledgement for the received reliable temporary response, namely,the 183 response, where the PRACK includes an early-session SDP answer 5for the early-session SDP offer 4.

610: The SCC AS sends a PRACK to the CAT AS, which serves as anacknowledgement for the received reliable temporary response, namely,the 183 response, where the PRACK includes an early-session SDP answer 4(generated based on the early-session SDP answer 5 and the mediainformation of the CS bearer) for the early-session SDP offer 4.

611: The CAT AS activates CAT media streams.

612: The CAT AS returns 200 OK to the SCC AS, which serves as anacknowledgment for the PRACK.

613: The SCC AS sends 200 OK to UE 1, which serves as an acknowledgmentfor the PRACK.

According to the preceding process 601-613, UE1 is connected to the CATmedia server through the CS bearer, so that the CAT service is performedwhen UE 1 and the called UE 3 set up a second ICS session (that is, UE 1receives the CAT media streams through the CS bearer). The followingsteps describe that UE 1 is connected to the called UE 3 through the CSbearer to implement a session function, and are specifically as follows:

614: The SCC AS receives a 200 OK off-hook signal sent by the CAT AS.

The 200 OK off-hook signal does not include the regular session mediainformation, and the SCC AS has saved the regular session mediainformation in step 606.

615: The CAT AS stops the CAT media streams.

616: The SCC AS sends an UPDATE or a re-INVITE that includes a new SDPoffer 5 to the MGCF or the MSC Server, where the SDP offer 5 includesthe regular session media information.

617: The MGCF or the MSC Server returns 200 OK to the SCC AS.

Till now, a media connection is established between UE 3 and the CSbearer.

618: The SCC AS sends 200 OK to UE 1, to indicate that the session setupis successful (UE 3 is already off-hook).

619: UE 1 sends an ACK to the SCC AS, which serves as an acknowledgmentfor 200 OK.

620: The SCC AS sends an ACK to the CAT AS, and the CAT AS sends an ACKto UE 3.

At this time, UE 1 transmits session media streams with UE 3 through theCS bearer, to perform a regular session.

The Gm interface is taken as an example in this embodiment of thepresent invention, and the method provided in this embodiment of thepresent invention is also applicable to an I1 interface.

In the method according to this embodiment of the present invention, ina scenario where the early-session model is used for the CAT service,the SCC AS sends CAT early session media information to the MSC Serveror the MGCF of a circuit switched network in the form the regularsession media information, where two cases that the received reliabletemporary response carries the early session SDP offer but does notcarry the regular session SDP answer, and that the received 1xxtemporary response carries both the early-session SDP offer and theregular session SDP answer are taken as examples. Therefore, a problemthat the CAT service cannot be used normally when the early-sessionmodel is used to set up the second ICS session is solved, therebyimproving use experience of a user.

In the method according to this embodiment of the present invention,when the early-session model is used for the CAT service, the SCC ASreceives the CAT early session media information through theearly-session SDP offer, and sends the CAT early session mediainformation to the MSC Server or the MGCF of the circuit switchednetwork in the form of regular session media information, so that thecircuit switched bearer is used for a CAT early session. The SCC ASreceives the off-hook signal of the third party (the off-hook signal andthe CAT early session media information come from the same dialog), andsends the regular session media information of the third party to theMSC Server or the MGCF of the circuit switched network, so that thecircuit switched bearer is used for the regular session, thereby solvinga problem that the MSC Server or the MGCF cannot support the CAT servicewhen the second ICS session is set up, and improving the use experienceof the user.

Embodiment 4

For a scenario where multiple user equipments of a called party cause aforking response during setup of a second ICS session, this embodimentof the present invention provides a service control method. A Gminterface is taken as an example for description, the specific contentis as follows:

First, UE 1 and UE 2 have already set up an ICS session (UE 1 transmitssession control signaling with an SCC AS by using a Gm interface), andimplement a call. Session media streams are transmitted through a CSbearer. Then, UE 1 holds (hold) UE 2 and initiates a session with UE 3.Referring to FIG. 7, the specific processing process is as follows:

701: UE 1 sends an INVITE 1 message to an SCC AS, to initiate a sessionwith a third party (a user), where the INVITE message includes an SDPoffer 1, and the SDP offer 1 indicates that the session uses the CSbearer.

702: The SCC AS receives the INVITE 1 message, and sends a re-INVITEthat does not carry the SDP offer to an MSC Server or an MGCF.

703: The MSC Server or the MGCF returns 200 OK that includes an SDPoffer 2, where the SDP offer 2 carries media information of the CSbearer.

If the SCC AS has already saved the media information of the CS bearer,steps 702 and 703 may be skipped.

704: The SCC AS generates a new SDP offer 3 based on the SDP offer 1 andthe media information of the CS bearer, and sends the SDP offer 3 to aCSCF (Call Session Control Function) of the third party through a newINVITE 2.

705: The CSCF of the third party performs a forking operation on theINVITE 2, thereby forking the INVITE 2 to user equipments 3 and 4 of thethird party.

706: A reliable temporary response 183 (including media information) ofUE 3 arrives at the SCC AS prior to that of UE 4, where D1 in the figureindicates a SIP Dialog ID1.

707: The SCC AS sends a reliable temporary response 183 that includesmedia information of UE 3 to UE 1.

708: UE 1 returns a PRACK to the SCC AS, which serves as anacknowledgment for the received reliable temporary response 183.

709: The SCC AS sends a PRACK to UE 3, which serves as an acknowledgmentfor the received reliable temporary response 183.

710: UE 3 returns 200 OK to the SCC AS, which serves as anacknowledgment for the PRACK.

711: The SCC AS sends 200 OK to UE 1, which serves as an acknowledgmentfor the PRACK.

712: The SCC AS sends an ACK to the MGCF or the MSC Server, which servesas an acknowledgment for the 200 OK in step 703.

The ACK sent by the SCC AS includes the media information of UE 3, sothat the CS bearer is connected to UE 3.

Through the preceding process 701-712, UE 1 is connected to UE 3 throughthe CS bearer, and waits UE 3 to send an off-hook signal.

If steps 702, 703 and 712 are not performed, the SCC AS sends the mediainformation of UE 3 to the MGCF or the MSC Server through an UPDATE or are-INVITE, so that the CS bearer is connected to UE 3.

713: A reliable temporary response 183 (including media information) ofUE 4 arrives at the SCC AS, where D2 in the figure indicates a SIPDialog ID2.

714-718: The SCC AS processes the 183 response of UE 4 in the same wayas processing of the 183 response of UE 3, except that the mediainformation of UE 4 is not immediately sent to the MGCF or the MSCserver.

719 a: The off-hook signal of UE 4 arrives at the SCC AS prior to thatof UE 3.

719 b-719 c: The SCC AS obtains the media information from UE 4 througha re-INVITE that does not carry SDP, that is, the SCC AS sends are-INVITE that does not carry SDP to UE 4, and UE 4 returns the mediainformation through 200 OK; or the SCC AS sends an UPDATE (including themedia information of the CS bearer) to UE 4, and UE 4 returns the mediainformation through 200 OK.

720-721: The SCC AS sends the media information of UE 4 to the MGCF orthe MSC Server through an UPDATE or a re-INVITE, so that the CS beareris connected to UE 4.

722-724: The SCC AS sends a 200 OK off-hook signal to UE 1; UE 1 sendsan ACK acknowledgment to the SCC AS; and the SCC AS sends an ACKacknowledgement to UE 4.

At this time, a media connection is established between UE 4 and the CSbearer. UE 1 transmits session media streams with UE 4 through the CSbearer, to perform a regular session. UE 3 is released subsequently.

In the method according to this embodiment of the present invention,after receiving media information of a called UE, the SCC AS sends themedia information to the MGCF or the MSC Server of a CS network. The SCCAS does not immediately send subsequently received media information ofanother called UE to the CS network, and after receiving an off-hooksignal of a certain called UE, the SCC AS sends media information of theUE to the CS network, thereby solving a problem that the MGCF or the MSCServer cannot support forking of multiple user equipments of a calledparty (the third party) during the second ICS session, and improving useexperience of a user.

Embodiment 5

For a scenario where a gateway model is used for a CAT service duringsetup of a second ICS session, this embodiment of the present inventionprovides a service control method, the specific content is as follows:

When receiving a response carrying CAT media information, an SCC ASsends the CAT media information carried in the response to an MSC Serveror an MGCF in a form of regular session media information, so as toconnect a CS bearer and a CAT media server. The CAT media server may beintegrated with a CAT application server (CAT AS, in this embodiment,the CAT AS provides the CAT service by using the gateway model), or maybe an independent media processing server for playing CAT media streams.After receiving regular session media information of a called-party UE,the SCC AS sends the regular session media information of thecalled-party (third-party) UE to the MSC Server or the MGCF (the MSCServer or the MGCF is an edge device of a CS network, and used forinterconnection between the CS network and an IMS network) through anUPDATE or a re-INVITE, so as to connect the CS bearer and thecalled-party (third-party) UE.

First, UE 1 (an ICS UE) and UE 2 has set up an ICS session (UE 1transmits service control signaling with the SCC AS over a Gm interface,where the Gm interface is implemented through a PS network), andimplement a call. Session media streams are transmitted through the CSbearer. Then, UE 1 holds (hold) the session and initiates a session withUE 3. Referring to FIG. 8, the specific processing process is asfollows:

801: UE 1 sends a SIP INVITE 1 message to the SCC AS through the Gminterface, to initiate a session with UE 3.

The INVITE message includes an SDP offer 1, where the SDP offer 1indicates that the session uses the CS bearer. SDP stands for thesession description protocol, and an SDP offer/answer mechanism is usedto perform session negotiation. SIP stands for the session initiationprotocol, and all messages in this process are SIP messages.

802: The SCC AS receives the INVITE 1 message, and sends a re-INVITEthat does not carry an SDP offer to the MSC Server or the MGCF.

803: The MSC Server or the MGCF returns 200 OK that includes an SDPoffer 2, where the SDP offer 2 carries media information of the CSbearer.

If the SCC AS has already saved the media information of the CS bearer,steps 402 and 403 may be skipped.

804: The SCC AS generates a new SDP offer 3 based on the SDP offer 1 andthe SDP offer 2, and sends the SDP offer 3 to a CAT AS through a newINVITE 2.

The CAT AS is a home AS of UE 3.

805 a-305 c: The CAT AS reserves CAT resources; the CAT AS forwards theSDP offer 3 to UE 3 through a new INVITE 3; and UE 3 returns a 180response to the CAT AS.

806: The CAT AS sends a reliable temporary response, namely, a 183response, to the SCC AS.

The 183 response includes an SDP answer 3 for the SDP Offer 3, where theSDP answer 3 includes CAT media information, and a P-Early-Media headerfield (for example, P-Early-Media: sendrecv and P-Early-Media: sendonly)may be used to indicate existence of CAT early media information.Definitely, any other manner may also be used for indication, which isnot limited in this embodiment of the present invention.

807: The SCC AS sends an ACK to the MGCF or the MSC Server.

The ACK sent by the SCC AS includes an SDP answer 2 for the SDP Offer 2,where the SDP answer 2 includes the CAT media information (or mayinclude a part of the CAT media information, and the rest part of theCAT media information may be transmitted through the PS network), sothat the CS bearer is connected to the CAT media server.

The ACK carries the CAT media information in a form of regular sessionmedia information, that is, the ACK does not include early mediaindication information. The MSC Server or the MGCF regards that themedia information is used for a regular session.

If steps 802, 803 and 807 are not performed, the SCC AS sends the CATmedia information to the MGCF or the MSC Server through an UPDATE or are-INVITE.

808: The SCC AS sends a reliable temporary response, for example, a 183response, which includes an SDP answer 1 for the SDP Offer 1, to UE 1through the Gm interface, where the SDP answer 1 includes the CAT mediainformation, which mainly enables UE 1 to know existence of the CATservice and/or to perform a CAT control operation. It is also possiblethat a part of the CAT streams is transmitted through the PS network.

809: UE 1 returns a PRACK to the SCC AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

810: The SCC AS sends a PRACK to the CAT AS, which serves as anacknowledgment for the received reliable temporary response, namely, the183 response.

811: The CAT AS activates the CAT media streams.

812: The CAT AS returns 200 OK to the SCC AS, which serves as anacknowledgment for the PRACK.

813: The SCC AS sends 200 OK to UE 1, which serves as an acknowledgmentfor the PRACK.

According to the preceding process 801-813, UE1 is connected to the CATmedia server through the CS bearer, so that the CAT service is performedwhen UE 1 and the called UE 3 set up a second ICS session (that is, UE 1receives the CAT media streams through the CS bearer). The followingsteps describe that UE 1 is connected to the called UE 3 through the CSbearer to implement a practical call, and are specifically as follows:

814 a-814 c: The CAT AS receives a 200 OK off-hook signal that is sentby UE 3 and includes an SDP answer 4 for the SDP Offer 3, where the SDPanswer 4 includes regular session media information (that is, mediainformation of the called UE 3). The CAT AS sends the regular sessionmedia information (serving as the SDP Offer 4) to the SCC AS through anUPDATE or a re-INVITE, and the SCC AS returns 200 OK.

815: The CAT AS stops the CAT media streams.

816: The SCC AS sends an UPDATE or a re-INVITE that includes a new SDPoffer 5 to the MGCF or the MSC Server, where the SDP offer 5 includesthe regular session media information of UE 3.

817: The MGCF or the MSC Server returns 200 OK to the SCC AS.

818-819: The SCC AS sends an UPDATE (or a re-INVITE) that carries theregular session media information of UE 3 to UE 1, and UE 1 returns 200OK.

820: The CAT AS sends a 200 OK off-hook signal to the SCC AS.

The off-hook signal 200 OK response, the UPDATE (or re-INVITE) messagein step 814, and the 183 response in step 806 are sent through one samedialog (dialog).

821: The SCC AS sends a 200 OK off-hook signal to UE 1, to indicate thatthe session setup is successful.

822: UE 1 sends an ACK to the SCC AS, which serves as an acknowledgmentfor the 200 OK.

823: The SCC AS sends an ACK to the CAT AS, and the CAT AS sends an ACKto UE 3.

Till now, a media connection is established between UE 3 and the CSbearer. UE 1 transmits the session media streams with UE 3 through theCS bearer, to perform the regular session (that is, the practical call).

The process is also applicable to a case of I1 interface, with an onlydifference that, I1 interface application protocol messages rather thanSIP messages are used between ICS UE 1 and the SCC AS.

In the method according to this embodiment of the present invention,when the gateway model is used for the CAT service, the SCC AS sends CATearly session media information to the MSC Server or the MGCF in theform of regular session media information, so that the circuit switchedbearer is used for a CAT early session. After the SCC AS receives theregular session media information of UE 3, where the regular sessionmedia information and the CAT early session media information come fromone same dialog, the SCC AS sends the regular session media informationto the MSC Server or the MGCF, so that the circuit switched bearer isused for the regular session, thereby solving a problem that the MSCServer or the MGCF cannot support the early session during setup of thesecond ICS session, and improving use experience of a user.

Embodiment 6

Referring to FIG. 9, this embodiment of the present invention provides aservice centralization and continuity application server SCC AS, where auser equipment has established a circuit switched bearer, and the userequipment initiates a session with a third party. The SCC AS includes:

an early session media information processing module 901, configured toreceive early session media information, and send the early sessionmedia information to a circuit switched network in s form of regularsession media, so that the circuit switched bearer is used for an earlysession; and

a regular session media information processing module 902, configured toreceive an off-hook signal of the third party, and send regular sessionmedia information of the third party to the circuit switched network, sothat the circuit switched bearer is used for a regular session; orconfigured to receive the regular session media information of the thirdparty, where the regular session media information of the third partyand the early session media information come from one same dialog, andsend the regular session media information of the third party to thecircuit switched network, so that the circuit switched bearer is usedfor the regular session.

In this embodiment, the regular session media information processingmodule 902 includes at least one of the following units:

a first processing unit, configured to receive and save the regularsession media information of the third party when or before receivingthe off-hook signal of the third party; and

a second processing unit, configured to obtain the regular session mediainformation from the third party after receiving the off-hook signal ofthe third party.

In this embodiment, the early session media information processingmodule 901 further includes:

a third processing unit, configured to receive and save the regularsession media information of the third party when or before receivingthe early session media information.

In this embodiment, a gateway model or a forking model or anearly-session model is used for the early session.

In addition, referring to FIG. 10, this embodiment of the presentinvention further provides a service centralization and continuityapplication server SCC AS, where a user equipment has established acircuit switched bearer, and the user equipment initiates a session witha third party. The SCC AS includes:

a first user equipment processing module 1001, configured to receiveregular session media information of a first user equipment of the thirdparty, and send the regular session media information of the first userequipment of the third party to a circuit switched network, so that thecircuit switched bearer is used for connecting the first user equipmentof the third party; and

a second user equipment processing module 1002, configured to receive anoff-hook signal of a second user equipment of the third party, and sendregular session media information of the second user equipment of thethird party to the circuit switched network, so that the circuitswitched bearer is used for connecting the second user equipment of thethird party.

In this embodiment, the second user equipment processing module 1002includes at least one of the following units:

a fourth processing unit, configured to receive and save the regularsession media information of the second user equipment of the thirdparty when or before receiving the off-hook signal of the second userequipment of the third party; and

a fifth processing unit, configured to obtain the regular session mediainformation from the second user equipment of the third party afterreceiving the off-hook signal of the second user equipment of the thirdparty.

Embodiment 7

This embodiment of the present invention provides a service controlsystem, and referring to FIG. 11, the system includes a user equipment1101 and an SCC AS 1102, where

the user equipment 1101 is configured to set up a first ICS session witha circuit switched bearer, and initiate a second ICS session with athird party; and

the SCC AS 1102 is configured to receive early session mediainformation, and send the early session media information to a circuitswitched network, so that the circuit switched bearer is used for anearly session; configured to receive an off-hook signal of the thirdparty, and send regular session media information of the third party tothe circuit switched network, so that the circuit switched bearer isused for a regular session; and further configured to receive theregular session media information of the third party, where the regularsession media information of the third party and the early session mediainformation come from one same dialog, and send the regular sessionmedia information of the third party to the circuit switched network, sothat the circuit switched bearer is used for the regular session.

The SCC AS 1102 further includes at least one of the following modules:

a first processing module, configured to receive and save the regularsession media information of the third party when or before receivingthe off-hook signal of the third party;

a second processing module, configured to obtain the regular sessionmedia information from the third party after receiving the off-hooksignal of the third party; and

a third processing module, configured to receive and save the regularsession media information of the third party before receiving the earlysession media information.

Referring to FIG. 12, this embodiment of the present invention furtherprovides a service control system, which includes a user equipment 1201and an SCC AS 1202, where

the user equipment 1201 is configured to set up a first ICS session witha circuit switched bearer, and initiate a second ICS session with athird party; and

the SCC AS 1202 is configured to receive regular session mediainformation of a first user equipment 1201 of the third party, and sendregular session media information of the first user equipment 1201 ofthe third party to a circuit switched network, so that the circuitswitched bearer is used for connecting the first user equipment 1201 ofthe third party; and further configured to receive an off-hook signal ofa second user equipment 1201 of the third party, and send regularsession media information of the second user equipment 1201 of the thirdparty to the circuit switched network, so that the circuit switchedbearer is used for connecting the second user equipment 1201 of thethird party.

The SCC AS 1202 further includes at least one of the following modules:

a fourth processing module, configured to receive and save the regularsession media information of the second user equipment 1201 of the thirdparty when or before receiving the off-hook signal of the second userequipment 1201 of the third party; and

a fifth processing module, configured to obtain the regular sessionmedia information from the second user equipment 1201 of the third partyafter receiving the off-hook signal of the second user equipment 1201 ofthe third party.

In the system according to this embodiment of the present invention, theSCC AS sends the early session media information to the CS network inthe form of regular session media, or the SCC AS saves second regularsession media information caused by forking execution instead ofimmediately sending the information to the CS network, thereby screeningthe early session or forking execution for the MSC Server or the MGCF ofthe CS network during a setup process of the second ICS session, andsolving problems that the MSC server or the MGCF does not support theearly media and that when an ICS UE initiates the second ICS session,forking of multiple user equipments 1201 of a called party (the thirdparty) cannot be supported. Therefore, use experience of a user isimproved.

Finally, it should be noted that persons of ordinary skill in the artshould understand that all or a part of the processes of the methodsaccording to the embodiments of the present invention may be implementedby a program instructing relevant hardware. The program may be stored ina computer readable storage medium. When the program is run, theprocesses of the methods according to the embodiments of the presentinvention are performed. The storage medium may be a magnetic disk, anoptical disk, a read-only memory (ROM), a random access memory (RAM),and so on.

The functional units in the embodiments of the present invention mayeither be integrated in a processing module, or be a separate physicalunit respectively; alternatively, two or more of the units may beintegrated in one module. The integrated modules may be implemented inthe form of hardware or software functional modules. If implemented inthe form of software functional modules and sold or used as anindependent product, the integrated modules may also be stored in acomputer readable storage medium. The storage medium may be a read-onlymemory, a magnetic disk, an optical disk, and so on. The foregoingapparatuses or systems may perform methods in the corresponding methodembodiments.

The preceding embodiments are merely exemplary embodiments of thepresent invention, and are not intended to limit the present invention.Any modifications, equivalent replacements or improvement withoutdeparting the spirit and principle of the present invention shall fallwithin the protection scope of the present invention.

1. A service control method, wherein a user equipment has established acircuit switched bearer, the user equipment initiates a session with athird party, and the method comprises: receiving, by a servicecentralization and continuity application server (SCC AS), early sessionmedia information, and sending the early session media information to acircuit switched network in a regular session media form, so that thecircuit switched bearer is used for an early session; receiving, by theSCC AS, an off-hook signal of the third party, and sending regularsession media information of the third party to the circuit switchednetwork, so that the circuit switched bearer is used for a regularsession.
 2. The method according to claim 1, wherein a manner ofobtaining the regular session media information of the third partycomprises: receiving and saving, by the SCC AS, the regular sessionmedia information of the third party when or before the SCC AS receivesthe off-hook signal of the third party.
 3. The method according to claim1, wherein a manner of obtaining the regular session media informationof the third party comprises: obtaining, by the SCC AS, the regularsession media information from the third party after the SCC AS receivesthe off-hook signal of the third party.
 4. The method according to claim1, wherein a manner of obtaining the regular session media informationof the third party comprises: receiving and saving, by the SCC AS, theregular session media information of the third party when or before theSCC AS receives the early session media information.
 5. A servicecentralization and continuity application server (SCC AS), wherein auser equipment has established a circuit switched bearer, the userequipment initiates a session with a third party, and the SCC AScomprises: an early session media information processing module,configured to receive early session media information, and send theearly session media information to a circuit switched network in aregular session media form, so that the circuit switched bearer is usedfor an early session; and a regular session media information processingmodule, configured to receive an off-hook signal of the third party, andsend regular session media information of the third party to the circuitswitched network, so that the circuit switched bearer is used for aregular session.
 6. The SCC AS according to claim 5, wherein the regularsession media information processing module comprises at least one ofthe following units: a first processing unit, configured to receive andsave the regular session media information of the third party when orbefore receiving the off-hook signal of the third party; and a secondprocessing unit, configured to obtain the regular session mediainformation from the third party after receiving the off-hook signal ofthe third party.
 7. The SCC AS according to claim 5, wherein the earlysession media information processing module further comprises: a thirdprocessing unit, configured to receive and save the regular sessionmedia information of the third party when or before receiving the earlysession media information.